You may need to add sites with both with and without the "www.". Test after blocking to make sure you got it right.
You can add as many sites as you wish to block in this fashion. I, myself, have over 12000 undesireable and dangerous sites in my personal HOSTS file!
4. Close Notepad and answer "Yes" when prompted.
5. Reboot your computer and attempt to access your now blocked website. You should see a Cannot find server or DNS Error saying: "The page cannot be displayed".
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Some people suggest that you add a website that you wish to block by adding it to Internet Explorer's Restricted Zone. This does NOT totally block a site. It will only RESTRICT a site from certain actions such as using javascript, Active-X and Java etc.
Some people suggest that your add a website to the Internet Explorer 'Privacy' settings. This does not block a site. It only stops that site from using cookies.